English verb conjugation
MUST VAIL

Regular verb: vail - vailed - vailed

Affirmation

Simple form	V-ing form
I must vail you must vail he must vail we must vail you must vail they must vail	I must be vailing you must be vailing he must be vailing we must be vailing you must be vailing they must be vailing
Perfect	V-ing perfect
I must have vailed you must have vailed he must have vailed we must have vailed you must have vailed they must have vailed	I must have been vailing you must have been vailing he must have been vailing we must have been vailing you must have been vailing they must have been vailing

Negation

Simple form	V-ing form
I mustn't vail you mustn't vail he mustn't vail we mustn't vail you mustn't vail they mustn't vail	I mustn't be vailing you mustn't be vailing he mustn't be vailing we mustn't be vailing you mustn't be vailing they mustn't be vailing
Perfect	V-ing perfect
I mustn't have vailed you mustn't have vailed he mustn't have vailed we mustn't have vailed you mustn't have vailed they mustn't have vailed	I mustn't have been vailing you mustn't have been vailing he mustn't have been vailing we mustn't have been vailing you mustn't have been vailing they mustn't have been vailing

Interrogative form

Simple form	V-ing form
must I vail? must you vail? must he vail? must we vail? must you vail? must they vail?	must I be vailing? must you be vailing? must he be vailing? must we be vailing? must you be vailing? must they be vailing?
Perfect	V-ing perfect
must I have vailed? must you have vailed? must he have vailed? must we have vailed? must you have vailed? must they have vailed?	must I have been vailing? must you have been vailing? must he have been vailing? must we have been vailing? must you have been vailing? must they have been vailing?

Interro-negative form

Simple form	V-ing form
mustn't I vail? mustn't you vail? mustn't he vail? mustn't we vail? mustn't you vail? mustn't they vail?	mustn't I be vailing? mustn't you be vailing? mustn't he be vailing? mustn't we be vailing? mustn't you be vailing? mustn't they be vailing?
Perfect	V-ing perfect
mustn't I have vailed? mustn't you have vailed? mustn't he have vailed? mustn't we have vailed? mustn't you have vailed? mustn't they have vailed?	mustn't I have been vailing? mustn't you have been vailing? mustn't he have been vailing? mustn't we have been vailing? mustn't you have been vailing? mustn't they have been vailing?